Question about 545 primer

[mrybas]

Originally Posted by Zach

Is that a current picture of the state of things?


If so, don't 545... Hit her with another round of Awlquick.


Before you do that... Take a straight edge/sheet rock trowel or even the side of your board and hold it up tight to the hull and see if it rocks.



Lay it on top of the awlfair patches, parallel the the waterline, long ways to the boat. Take a flash light and shine it under, and look for light in a crack. Anything that has changed color after sanding primer has shown its self as a high spot, or the edge of a low spot that the board is dropping into and riding into the putty you filled.



With that hard of a straight edge around your putty fills... They are normally a high spots that didn't get feathered in, up top by the deck line. If the straight edge, sheet rock trowel, or squeedgee rocks or shows light under it you'll burn the next layer of primer off the high spots again.



If you don't have guide coat, you can squiggle pencil lines around the high spots and on top of the high spots and sand until the pencil lines disappear. The board ramps up on to the high and a squiggle of pencil line disappear off the top of the high, but right where the color change is hard to sand the pencil lines off out unless you hold the board flat and sand straight into it repeatedly without going over it in long passes.



Boarding if you let the board float over the the surface with more pressure on the trailing edge than the leading edge and coarse paper, it'll work the highs down, but if they are built up with a series of fills in a row and the first one is high you end up with a putty ramp.



I call high spots that are putty with vertical edges putty flags, as a straight edge and a bright light will show a crack. The board can go across them and sand off the primer up to the edge, and all the primer over the top of them because it lifts the board up and over, and they are just hard enough material that you burn the primer off around them before they get level to the surrounding surface.

Most folks prime something because the fairing work is pretty good and want to take a look at it one color. Then once it is primed, forget that they were just trying to take a look because it was one color and try to race to finish primer.



If you've got a few spots that need a little more sanding, drop back to coarse grits in localized areas and beat the trouble spots down to where they need to be. A lot of guys once they pick up a roller brush or spray gun won't go back to a grit that cuts harder materials fast enough to level out the surface and mow them down.



Makes for a never ending priming job of trying to put just one more coat over a high spot of bare fiberglass or putty so you can spray top coat. Make trouble spots ever so slightly low and prime them up... Don't have to think about or ever see them again without the kidd glove sanding and panic attack...



A holiday, or slight groove in the putty that has been primed shows as a thick colored primer line in it. More often than not if you sand down til the primer in the holiday is gone in the putty, the flag feathers out and disappears and you are even with the surrounding surface. Basically, putty fills should taper in from a barely visible thickness in color to something dark in the middle and not be square sqaped.



If you look under the left side of the saddle up on deck straight above you, the putty flag that has a thick white bit of primer to its left hand side is a holiday where the primer is thick. Either it needed another fill of putty where the holiday is... or it is a high spot where the primer sanded off and is showing Awlfair.


Sort of a topographical map type thing...



If the green is bare glass, then you can't get there from here as the board digs a halo around each of those as 120 will shred the primer off before you even think about taking down the glass.



They reappear immediately after you prime unless you burn them down or cover the entire surface in enough primer that you can sand it out. That is gallons of material. High build/ultrabuild can do that but it takes a LOT of material to do that.



For putty flags and holidays you can drop back to 80 grit on a hand block guide coat it, sand til smooth and then work back up the grits to 220 and prime an area at a time if you only have a few trouble spots in a 2x4 foot or 4x4 foot area.


The area will be slightly low after mowing it down and really beating on it... but if you put 3 coats of Awlquick over just the areas you have worked on they end up flush and one color to the surrounding surface once you sand it back slick and feather in from the surrounding area you are calling good.



I like to roll repaired areas, as roller stipple gives you some idea of depth of issues and you lose less material to overspray. Weenie rollers or 1/8th inch nap foam work fine, and ray charles can see where you haven't sanded. Spraying in little areas as you go is harder to not miss something.



Almost always, it is better to end up ever so slightly low after sanding putty fills that are done with squeedgees and putty knives instead of screeds and battens. Otherwise they end up 4-6 inch wide high spots instead of perfect to perfect to the surrounding area but out of a much harder material.



Until you get all those beaten down shooting the whole boat just means sanding the whole boat until you find them again and eventually either raise the primer above them, or sand them off.


If you can get 220 grit smooth, and all one color the 545 will stay on the boat when you go to sand it out with 320. Much less than that, and it is a wipe on, wipe off process that you never quite get out of.



How many gallons are you going to put on? I would try my best to put a mixed gallon before adding thinner on each side to have enough material to get out of thew woods.



Lastly, it looks like you've done a real good job sanding out the putty fills at your current working height. I'd look at what it takes to get your staging set up around the boat to get the top of the hull up by the deck sanded at the same shoulder height. Where it hurts to work, is the hardest part to get down fair... But normally also the most visible. Right above the waterline is hard to see on a boat in the water because of all the light reflections. Walking down the dock, the deck line is what most folks see.



My rule of thumb on DA's and power sanding in general is that you can change the material color, and power sand. Once you start burning through what you've done is moved forward a grit and smoothed things out.



Gist of it is when throwing power at something... Is if you prime and sand off everything except what you can't sand off without removing filler... You've filled your low spots and highlighted your high spots, but at some point you better stop before you lose your point of reference and start making low spots. Boards can make low spots but you've got to work your ass off to do it.



If I were in your shoes, I'd consider guide coating and throwing some 80 grit on the board and do a pass down the hull one way, a pass down the hull the other and go look at your putty flags and see if you've got contact around and up over them. If you have areas that are 180 grit smooth with just a kiss here and there of 80 grit scratches, you jumped to a fine grit before your high spots were worked out.



The catch 22 of board sanding is if you try to slick out and get shiny before it is fair in coarse grits, you never get done priming. Sometimes the fastest way forward is to be a little mean, and pile up some dust on the floor and get things flat enough that they stay one color on the next sanding.

Holy Cow Zach, I wish I would have had your input before starting the fairing process!
I’ve already been sanding for 100 of hours and don’t think I have it in me to do another coat of awlquick. I’ll be happy with an 8/10 finish.

I have planks set up on ladders,
So it’s easy to change my working height and never working over a comfortable height.

Thanks for your advice, you are a real pro and glad your willing to help a newbie out!

[Zach]

Understood on sanding enough already.


Spray your awlquick, then follow the recoat window and spray your 545 without sanding in between. You might get out of the woods, but will probably need a few more 545's to get there from where you are.



545 on its own at its full wet mil thickness won't fill 180 grit scratches and build. It'll do one or the other.



My rule of thumb for 545, is roughly a pint in a conventional gun per 5x10ft area, per shot... with three shots per coat. Figure out roughly how many times you need to refill the gun on the first coat, and then hope you've got an extra 2 gallons more than what you thought you needed on the floor ready to go.


Spraying on weekends is tough on that count, if you come up shy on material it means sanding for adhesion on the next coat and a lot more labor... or paying straight retail for the material.



I'd mix a gallon at most, and see if it covers what you think it will cover. Pick your stairs, spray up 10 feet of the hull three shots and see what you think.


545 is world class finish primer and may as well be milk if you want it to fill.

[mrybas]

We sprayed 3 coats of 545 today. 3 kits (6 gallons) to spray from water line to 2” onto deck of both hulls.
I think it came out pretty good. Gave a quick attempt at spraying and at $100/gallon, quickly gave the gun back to my buddy!

[GRIT]

Congrats, she looks great. You must be excited!

Cheers.
Paul.

[GRIT]

That looks like a nice workshop. May I ask where you are located? Are you on the East Coast USA? I noticed your username says East Coast USA.

Is the shop yours, or a rental? I'd be interested in renting such a shop for a month or two. Fairing outside, in Sept, in Canada, is a bear, due mostly to dew.

Cheers.
Paul.

[mrybas]

Originally Posted by GRIT

That looks like a nice workshop. May I ask where you are located? Are you on the East Coast USA? I noticed your username says East Coast USA.



Is the shop yours, or a rental? I'd be interested in renting such a shop for a month or two. Fairing outside, in Sept, in Canada, is a bear, due mostly to dew.



Cheers.

Paul.

Hi Paul.
The ‘shop’ is an old greenhouse that I built around the boat. The boat is in my back yard which is along a creek that connects to the Delaware River. I had to hire a crane to pick the boat.

[Zach]

Looks good!

[GRIT]

I just saw your advertisement for selling the "shop". I wish I was closer. It'd be worth it, even this close to launch...

We had to crane too, just to turn the boat around in the yard, after removing it from the "shop".
The part of the boat that isn't white was in the shop, with just over a foot between the wall and the hull. Now we have to finish that 27 foot area (each side) before launch.

We used the chainplates in lieu of straps. We're 1km from the water, so we'll have to crane, and trailer through town for launch.

Cheers.
Paul.

[mrybas]

Originally Posted by GRIT

I just saw your advertisement for selling the "shop". I wish I was closer. It'd be worth it, even this close to launch...



We had to crane too, just to turn the boat around in the yard, after removing it from the "shop".

The part of the boat that isn't white was in the shop, with just over a foot between the wall and the hull. Now we have to finish that 27 foot area (each side) before launch.



We used the chainplates in lieu of straps. We're 1km from the water, so we'll have to crane, and trailer through town for launch.



Cheers.

Paul.

Looks sweet! What is the boat?

[GRIT]

Thanks.

It's based on a Kurt Hughes 45. We had him stretch the hulls 5 feet, and shrink the bridgedeck 6 feet.

The pilot house is mine, my balance isn't so good, and with the front cockpit, I won't have to get on deck much. Kurt doesn't like inside steering and front cockpits; my wife doesn't like me falling overboard. She wins.

Will you launch this year, or wait for warmer weather?

That crane doesn't look very big, the boat must be quite light!

Cheers.
Paul.

[mrybas]

Originally Posted by GRIT

Thanks.

It's based on a Kurt Hughes 45. We had him stretch the hulls 5 feet, and shrink the bridgedeck 6 feet.

The pilot house is mine, my balance isn't so good, and with the front cockpit, I won't have to get on deck much. Kurt doesn't like inside steering and front cockpits; my wife doesn't like me falling overboard. She wins.

Will you launch this year, or wait for warmer weather?

That crane doesn't look very big, the boat must be quite light!

Cheers.
Paul.

Hi Paul,
Your boat looks really sweet! I’ll pm you my email address. I’d like to see more pictures!

I was hoping to get S this fall, but my window is quickly closing and looks like I’ll be stuck here for the winter.

[GRIT]

Me too. We were going to launch this fall, but... boat building happens on it's own schedule.

Cheers.
Paul.

[mrybas]

Amazing what a little primer does for the spirit! I’ve spent hundreds of hours sanding with very little visual change. Now I can see where the time went!

[GRIT]

Well done, especially on the little bits. I find the little bits take as long as much larger, flatter, sections of hull. Finicky stuff those fittings.

Cheers.
Paul.

[GRIT]

Any updates on your paintjob? I'd love to see some photos.

Cheers.
Paul.